The mode field distributions of higher order mode of planar optical waveguide are analyzed by using the Finite-Difference Time. Domain (FD-TD) method. In this paper, the mode field distributions of TE, niode is analysed by using the vector FD-TD method at first; Then the mode field distributions of TE2 mode is analysed by using the scalar FD-TD method. The figures of mode field distributions calculated by conputer are identical to the conclusion discussed by else methods.